Microwave Cavity with Controllable Temperature for In Vitro Hyperthermia Investigations

Asimina Kiourti,Mingrui Sun,Xiaoming He,John L. Volakis 한국전자파학회JEES 2014 Journal of Electromagnetic Engineering and Science Vol.14 No.3

Hyperthermia is a form of cancer treatment in which affected human tissue is exposed to >40℃ temperature. In this paper, our goal is to assess the efficacy of fullerene agents to reduce heating time for cancer treatment. Such agents can accelerate heating of cancer cells and improve hyperthermia treatment efficacy. Typically, in vitro testing involves cancer cell culturing, heating cell cultures in accordance to specifications, and recording cancer cell viability after hyperthermia. To heat cell cultures, we design and evaluate a 2.4-GHz microwave cavity with controllable temperature. The cavity is comprised of a polystyrene cell culture dish (diameter = 54 mm, height = 13.5 mm) and a printed monopole antenna placed within the cavity for microwave heating. The culture temperature can be controlled through the intensity and duration of the antenna’s microwave radiation. Heating experiments were carried out to validate the cavity’s performance for F-12K culture medium (Kaighn’s F-12K medium, ATCC). Importantly, fullerene agents were shown to reduce heating time and improve hyperthermia treatment efficacy. The culture medium temperature increased, on average, from 24.0℃ to 50.9℃ (without fullerene) and from 24.0℃ to 56.8℃ (with 3 mg/mL fullerene) within 15 minutes.

Neurosurgical Management of Cerebrospinal Tumors in the Era of Artificial Intelligence : A Scoping Review

Kuchalambal Agadi,Asimina Dominari,Sameer Saleem Tebha,Asma Mohammadi,Samina Zahid 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.6

Central nervous system tumors are identified as tumors of the brain and spinal cord. The associated morbidity and mortality of cerebrospinal tumors are disproportionately high compared to other malignancies. While minimally invasive techniques have initiated a revolution in neurosurgery, artificial intelligence (AI) is expediting it. Our study aims to analyze AI’s role in the neurosurgical management of cerebrospinal tumors. We conducted a scoping review using the Arksey and O’Malley framework. Upon screening, data extraction and analysis were focused on exploring all potential implications of AI, classification of these implications in the management of cerebrospinal tumors. AI has enhanced the precision of diagnosis of these tumors, enables surgeons to excise the tumor margins completely, thereby reducing the risk of recurrence, and helps to make a more accurate prediction of the patient’s prognosis than the conventional methods. AI also offers real-time training to neurosurgeons using virtual and 3D simulation, thereby increasing their confidence and skills during procedures. In addition, robotics is integrated into neurosurgery and identified to increase patient outcomes by making surgery less invasive. AI, including machine learning, is rigorously considered for its applications in the neurosurgical management of cerebrospinal tumors. This field requires further research focused on areas clinically essential in improving the outcome that is also economically feasible for clinical use. The authors suggest that data analysts and neurosurgeons collaborate to explore the full potential of AI.

Evaluation of Existing Combination Rules for the Effects caused by Three Spatial Components of an Earthquake

Athanasios G. Tsourekas,Asimina M. Athanatopoulou 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.7

The influence of the orientation of ground motion horizontal components on structural response within the context of Response History Analysis is investigated. For this purpose the maximum response to six R/C single storey structural models with different natural periods and mass eccentricity for many angles of seismic incidence due to seven ground motions is computed. Furthermore the maximum response values over all seismic incident angles produced by analytical formulas are compared to the ones produced by using the types of analysis suggested in the Nuclear Regulatory Guide. The results show that the types of analysis suggested in the Nuclear Regulatory Guide produce smaller response values than the maximum ones over all incident angles. Concerning the influence of the natural period on the difference between the response values produced by the types of analysis suggested in the Nuclear Regulatory Guide and the maximum ones over all seismic incident angles it is found that it is significant, however no specific trend is observed. Concerning the influence of the mass eccentricity it is found that it is not considerable.

Multimode pushover analysis based on energy-equivalent SDOF systems

Grigorios E. Manoukas,Asimina M. Athanatopoulou,Ioannis E. Avramidis 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.4

In this paper the extension of a recently established energy-based pushover procedure in order to include the higher mode contributions to the seismic response of structures is presented and preliminary evaluated. The steps of the proposed methodology in its new formulation are quite similar to those of the well-known Modal Pushover Analysis. However, the determination of the properties of the „modal‟ equivalent single-degree-of-freedom systems is achieved by a rationally founded energy-based concept. Firstly, the theoretical background and the assumptions of the proposed methodology are presented and briefly discussed. Secondly, the sequence of steps to be followed for its implementation along with the necessary equations is systematically presented. The accuracy of the methodology is evaluated by an extensive parametric study which shows that, in general, it provides better results compared to those produced by other similar procedures. In addition, the main shortcoming of the initial version of the methodology now seems to be mitigated to a large extent.

Multimode pushover analysis based on energy-equivalent SDOF systems

Manoukas, Grigorios E.,Athanatopoulou, Asimina M.,Avramidis, Ioannis E. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.4

In this paper the extension of a recently established energy-based pushover procedure in order to include the higher mode contributions to the seismic response of structures is presented and preliminary evaluated. The steps of the proposed methodology in its new formulation are quite similar to those of the well-known Modal Pushover Analysis. However, the determination of the properties of the 'modal' equivalent single-degree-of-freedom systems is achieved by a rationally founded energy-based concept. Firstly, the theoretical background and the assumptions of the proposed methodology are presented and briefly discussed. Secondly, the sequence of steps to be followed for its implementation along with the necessary equations is systematically presented. The accuracy of the methodology is evaluated by an extensive parametric study which shows that, in general, it provides better results compared to those produced by other similar procedures. In addition, the main shortcoming of the initial version of the methodology now seems to be mitigated to a large extent.

Effect of Lymphocyte Phenotypic Alterations on the Humoral Response to Vaccination Against SARS-COV-2 in Dialysis Patients

Lioulios Georgios,Fylaktou Asimina,Asouchidou Despina,Xochelli Aliki,Nikolaidou Vasiliki,Stai Stamatia,Christodoulou Michalis,Giamalis Panagiotis,Tsouchnikas Ioannis,Papagianni Aikaterini,Stangou Mari 대한진단검사의학회 2023 Annals of Laboratory Medicine Vol.43 No.5

Background: The response to vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) varies depending on comorbidities. This study evaluated the clinical and immunological factors affecting the humoral response of patients with end-stage renal disease (ESRD) to the BNT162b2 vaccine. Methods: Humoral immunity was evaluated in 54 ESRD patients using serum levels of anti-receptor-binding domain (RBD) and neutralizing antibodies (NAbs), measured by a chemiluminescent immunoassay 30 (T1), 60 (T2), and 120 (T3) days after the second vaccine dose. The results were correlated to baseline patient T- and B-lymphocyte subpopulations determined by flow cytometry. Results: The proportion of seroconverted patients based on the NAb titer decreased from 83.3% at Τ1 to 53.7% at Τ3. Age was negatively correlated to the NAb titer at T1 and Τ2. Patients receiving hemodiafiltration had higher NAb titers at T3. Diabetes was associated with a lower response rate at T3. Univariate analysis revealed a positive correlation between the naïve CD4 T-lymphocyte population and RBD titer at T1 and the NAb titer at T3, with no association observed with naïve CD8 T lymphocytes. NAb titers at T3 were significantly correlated with late-differentiated CD4 T lymphocytes and terminally differentiated effector memory cells re-expressing CD45RA (TEMRA) CD8 T lymphocytes. RBD levels were positively correlated with naïve and memory B-lymphocyte counts at T3. Conclusions: Age, diabetes, and hemodialysis prescription had significant impacts on the response to vaccination. T- and B-lymphocyte phenotypes are major determinants of the humoral response potency to SARS-CoV-2 vaccination with BNT162b2 in patients with ESRD.

Influence of Seismic Incident Angle on Response of Symmetric in Plan Buildings

Konstantinos G. Kostinakis,Grigorios E. Manoukas,Asimina M. Athanatopoulou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.2

The objective of this paper is the investigation of the influence of the seismic incident angle on the response values of symmetric in plan buildings subjected to bi-directional horizontal ground motion. Firstly, a set of symmetric buildings is studied by means of linear response history analysis. The maximum response values over all incident angles are determined using well established analytical formulae. It is demonstrated that for symmetric buildings possessing equal stiffness along two orthogonal horizontal axes the maximum value of some vectorial response quantities (resultant displacements, resultant moments of some columns) does not depend on the orientation of the seismic action. On the contrary, the seismic incident angle is essential for the rest response quantities of such buildings, as well as for all the response quantities of symmetric buildings with different stiffness along the two structural axes. In addition, the same buildings are analyzed by means of non-linear response history analysis, with seismic components having several different orientations with regard to the structural axes. Similar conclusions are derived for the nonlinear range of behaviour too.

Parameters affecting the seismic response of buildings under bi-directional excitation

Ioanna - Kleoniki M. Fontara,Konstantinos G. Kostinakis,Grigorios E. Manoukas,Asimina M. Athanatopoulou 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

The present paper investigates the influence of the orientation of the ground-motion reference axes, the seismic incident angle and the seismic intensity level on the inelastic response of asymmetric reinforced concrete buildings. A single storey asymmetric building is analyzed by nonlinear dynamic analyses under twenty bi-directional ground motions. The analyses are performed for many angles of incidence and four seismic intensity levels. Moreover three different pairs of the horizontal accelerogramscorresponding to the input seismic motion are considered: a) the recorded accelerograms, b) the corresponding uncorrelated accelerograms, and c) the completely correlated accelerograms. The nonlinear response is evaluated by the overall structural damage index. The results of this study demonstrate that the inelastic seismic response depends on the orientation of the ground-motion reference axes, since the three individual pairs of accelerograms corresponding to the same ground motion (recorded, uncorrelated and completely correlated) can cause different structural damage level for the same incident angle. Furthermore, the use of the recorded accelerograms as seismic input does not always lead to the critical case of study. It is also shown that there is not a particular seismic incident angle or range of angles that leads to the maximum values of damage index regardless of the seismic intensity level or the ground-motion reference axes.

Parameters affecting the seismic response of buildings under bi-directional excitation

Fontara, Ioanna-Kleoniki M.,Kostinakis, Konstantinos G.,Manoukas, Grigorios E.,Athanatopoulou, Asimina M. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

The present paper investigates the influence of the orientation of the ground-motion reference axes, the seismic incident angle and the seismic intensity level on the inelastic response of asymmetric reinforced concrete buildings. A single storey asymmetric building is analyzed by nonlinear dynamic analyses under twenty bi-directional ground motions. The analyses are performed for many angles of incidence and four seismic intensity levels. Moreover three different pairs of the horizontal accelerograms corresponding to the input seismic motion are considered: a) the recorded accelerograms, b) the corresponding uncorrelated accelerograms, and c) the completely correlated accelerograms. The nonlinear response is evaluated by the overall structural damage index. The results of this study demonstrate that the inelastic seismic response depends on the orientation of the ground-motion reference axes, since the three individual pairs of accelerograms corresponding to the same ground motion (recorded, uncorrelated and completely correlated) can cause different structural damage level for the same incident angle. Furthermore, the use of the recorded accelerograms as seismic input does not always lead to the critical case of study. It is also shown that there is not a particular seismic incident angle or range of angles that leads to the maximum values of damage index regardless of the seismic intensity level or the ground-motion reference axes.

Yield of Combined Impedance-pH Monitoring for Refractory Reflux Symptoms in Clinical Practice

( Georgios Karamanolis ),( Georgios Kotsalidis ),( Konstantinos Triantafyllou ),( Dimitrios Polymeros ),( Asimina Gaglia ),( Smaragdi Fessatou ),( Maria Triantafyllou ),( Ioannis Papanikolaou ),( Spir 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2011 Journal of Neurogastroenterology and Motility (JNM Vol.17 No.2

Background/Aims In patients with gastroesophageal reflux disease, persistent symptoms on proton pump inhibitor (PPI) therapy may be due to residual acid or non-acid reflux. Combined impedance-pH has been suggested to be superior to pH alone in the management of refractory patients to PPI. The utility of implementation of this technique in every day clinical practice is still unknown. The aim of this study was to investigate the outcomes of patients studied with combined impedance-pH and to evaluate the yield of additional impedance monitoring over pH alone in patients with persistent gastroesophageal reflux disease symptoms. Methods Seventy-one patients (31 men; mean age, 49.1 ± 15.5 years) on PPI therapy underwent combined impedance-pH for persistent typical (76%) or atypical (49%) symptoms. Results During impedance-pH study, 44 (62%) patients reported symptoms. A positive symptom index (SI) was found in 21 (48%) patients: 8 (18.2%) had a positive SI for acid reflux, 9 (20.5%) for non-acid reflux and 4 (9.1%) for mixed reflux. Addition of impedance allowed association between reflux and symptoms in 20.5% of patients who would have been missed by pH study alone. Heartburn was the most prevalent symptom associated with acid reflux, whereas regurgitation and ear, nose and throat symptoms were associated with non-acid reflux. Conclusions The use of combined impedance-pH monitoring substantially increased the diagnostic yield compared to pH alone. With SI analysis, 20.5% of patients received a diagnosis that could not have been achieved with pH testing alone. (J Neurogastroenterol Motil 2011;17:158-163)